The present invention relates to a push-button unit for a switch.
A known push-button switch unit is provided with a push-rod for actuating the electrical contact means of the switch. The push rod may be pushed in to displace the rod from an inoperative first position into a switch actuating position. Most known push-button switch units are constructed either as latching or as non-latching switches. In the first case, the push-rod, after being pushed in, is latchably retained in the switch-actuating position until it is again released by a renewed pressure. The push-rod can, for the attainment of this mode of operation, be provided with a guide groove, which forms a closed path cam and into which a latching element extends. In the second case, i.e. when the switch is constructed as non-latching switch, the guide groove and the latching element are absent so that the push-rod after being released always returns immediately from the switch-actuating position into the inoperative position.
With these previously known push-button switch units, a particular switch unit can thus in accordance with its construction be used either only as a latching switch or as a non-latching switch. Installation and switchboard construction firms thus must have available in their stores switches of both the aforementioned kinds. This represents a considerable disadvantage especially for smaller firms since the requirement at any time for such switch units of either of the aforementioned kinds may be subject to very strong fluctuations. Since the switch units can of course also still be equipped with different numbers of closing, opening and changeover contacts, such firms often find it necessary to maintain a relatively large stock of switch units in store.